Fits: 88-91 Prelude (2.0SI, SI)
This is a plug and play harness to bypass the increasingly problematic stock fan timer unit.
Versions: This wiring harness comes in 2 versions: Basic and advanced.
- Basic: You are running a B20a/B21a engine and stock ECU. Also works with engine swaps that don't require ECU fan control.
- Advanced: You have an engine swap and you want the OBD1 ECU to be able to control the radiator fans via the FANC (A12) pin.
The basic harness is just a simple timer bypass. The coolant temperature switch "A" at the bottom of the radiator will still turn on the fans above ~195F like usual. The basic harness will work with engine swaps as well, if you don't want the ECU fan control capability.
With the advanced harness installed the coolant temperature switch will still activate the fans above ~195F. However when you tap into the FANC (A12) pin at the ECU you will be able to control the exact temperature that the fans activate via tuning software (Hondata SManager). You would typically do this to have them turn on at a temperature below 195F. You aren't limited to activating them via a temperature switch at a fixed temperature.
Please see the install video for some more detail about the operation.
Install Instructions:
